Adult Feeding Experience Determines the Fecundity and Preference of the Henosepilachna vigintioctopunctata (F.) (Coleoptera: Coccinellidae)

TL;DR

The study shows that adult feeding experience in the ladybird beetle H. vigintioctopunctata determines its reproductive success and food preferences, regardless of its larval diet.

Contribution

The novel finding is that adult feeding experience, not larval experience, dictates adult fecundity and preferences in H. vigintioctopunctata.

Findings

Adult feeding host determines fecundity and preferences of H. vigintioctopunctata, independent of larval feeding experience.

Potato leaves are the optimal host, while eggplant leaves significantly reduce adult fecundity.

Host switching between larval and adult stages maintains population continuity but offers lesser performance benefits than a consistent potato diet.

Abstract

Both larvae and adults of the Henosepilachna vigintioctopunctata (F.) (Coleoptera: Coccinellidae) can feed on potato, tomato, and eggplant leaves, though potatoes serve as the most suitable host for the H. vigintioctopunctata. Owing to the differing planting times of potatoes, tomatoes, and eggplants, H. vigintioctopunctata adults must migrate to tomato or eggplant leaves for feeding to ensure continuous food availability. Therefore, under wild field conditions, host transfer between larvae and adults of the H. vigintioctopunctata is a normal phenomenon. Generally, the feeding experiences of both larval and adult hosts influence the survival and reproduction of the adult ladybird beetle. To ascertain the impact of larval and adult hosts on the performance and preference of adults, we allow H. vigintioctopunctata larvae and adults to either continue or change their feeding experience on potato, tomato, and eggplant leaves. Our results indicate that the adult feeding host dictates the fecundity and preferences of the adult, independent of the larval feeding experience. While host switching between larval and adult stages yields fewer benefits for H. vigintioctopunctata performance compared to a consistent potato leaf diet, it facilitates food access for H. vigintioctopunctata. Hence, under wild field conditions, we can adjust the planting intervals between eggplants, tomatoes, and potatoes to prevent host switching between larva and adult H. vigintioctopunctata, thereby ecologically controlling the populations of H. vigintioctopunctata.

Both larvae and adults of the Henosepilachna vigintioctopunctata feed on leaves of potatoes, tomatoes, and eggplants. Given the variation in planting times of host plants in the Jianghan Plain, host switching between larvae and adults of H. vigintioctopunctata is inevitable to ensure continuous food availability. We evaluated the effect of consistent versus diverse larval and adult host plant feeding experience on growth performance, fecundity, longevity, and feeding preferences of H. vigintioctopunctata through match-mismatch experiments. Host plant quality significantly influences larval development and adult reproduction. Potatoes are identified as the optimal host plant for H. vigintioctopunctata, whereas eggplants significantly negatively affect the adult fecundity. Adult stage host feeding experience determines the fecundity of H. vigintioctopunctata, irrespective of the larval feeding experience. The fecundity of H. vigintioctopunctata adults on eggplant leaves remains significantly lower than that observed on potato leaves. Similarly, adult H. vigintioctopunctata demonstrate a preference for consuming potato leaves, irrespective of the larval feeding experience. Although host switching between larval and adult stages offers lesser benefits for the performance of herbivorous insects compared to a consistent diet with potato leaves, it maintains H. vigintioctopunctata population continuity amidst shortages of high-quality potato hosts.

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